Technical Abstract:
Our laboratory has been researching the etiology of turkey osteomyelitis complex (TOC) for the past 16 years and we have determined that this syndrome is caused by the inability of some fast-growing male turkeys to cope with production stressors. While immunosuppressive viruses have traditionally been associated with susceptibility to gangrenous dermatitis (cellulitis), we hypothesize that production stress alone can also undermine resistance to opportunistic pathogens by disruption of the skin’s antimicrobial barrier resulting in the cutaneous and subcutaneous lesions referred to as cellulitis. Some of the common characteristics between TOC and cellulitis are that they are both caused by opportunistic bacterial species that are prevalent in the environment, they are both most common in male birds, and in both diseases the affected birds are often large, healthy, and from the best performing flocks. Our TOC studies using Dexamethasone immunosupression have resulted in a high incidence of cellulitis lesions in dead turkeys that were given either Escherichia coli or Staphylococcus aureus respiratory challenges. While clostridia species have not been studied using this model, their natural presence in the poultry environment suggests that they may also have been concomitant pathogens. We suggest that a useful model for cellulitis can be developed by focusing on the host response, particularly on the ability of stress to undermine the skin’s bacterial resistance in fast-growing male turkeys.